#include<bits/stdc++.h>
using namespace std;
int main()
{
	double a,reward=0,t;
	cin>>a;
	if(a>100) 
	{
		t=a-100;
		reward+=t*0.01;
		a-=t;
	}
	if(40<a&&a<=100)
	{
		t=a-40;
		reward+=t*0.03;
		a-=t;
	}
	if(10<a&&a<=40)
	{
		t=a-10;
		reward+=t*0.05;
		a-=t;
	}
	if(a<=10)
	reward+=a*0.1;
	printf("%.1f",reward*10000);
    return 0;
}
